An essay on dew, and several appearances connected with it / by William Charles Wells, M.D. F.R.S.
- William Charles Wells
- Date:
- 1814
Licence: Public Domain Mark
Credit: An essay on dew, and several appearances connected with it / by William Charles Wells, M.D. F.R.S. Source: Wellcome Collection.
Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.
29/162 page 19
![]9 cither less or no additional weight. This window is so situated, as to be, in great measure, deprived of the aspect of the sky. It being shewn, that wool, though highly at- tractive of dew, was prevented, by the mere vici- nity of a gravel walk, or bed of garden mould, for only a small part of it actually touched those bodies, from acquiring nearly as much dew, as an equal parcel laid upon grass, it may be readily inferred, that little was formed upon themselves. In confirmation of this conclusion, it may be said, that I never saw dew upon either of them. Ano- ther fact of the same kind is, that while returning to London from the scene of my experiments about sunrise, I never observed, if the atmosphere was clear, the public road, or stone pavement on the side of it, to be moistened with dew, though grass within a few feet of it, and painted doors and windows of houses not far from it, were frequently very wet. If, indeed, there was a foggy morning, after a clear and calm night, even the streets of London would sometimes be moist, though they had been dry the day before, and no rain had in the meanwhile fallen. This entire, or almost entire, freedom of certain situations from dew depends, however, much more upon extraneous circumstances, than upon the nature of the sub- stances found there; for river sand, though of the same nature with gravel, when placed upon the](https://iiif.wellcomecollection.org/image/b21299742_0029.jp2/full/800%2C/0/default.jpg)
